Introduced the optimiser module again, changing attribute access output to
employ an augmented version of the deducer's access plan format, adding
attribute ambiguity information.
1a=4 2 3deff(x): 4ifnotx: 5defg(y): 6returnx,y,a 7returng# UnboundLocalError: not defined if x is true 8 9result=f(1)(2) 10assertresult==(1,2,4)